Time-weighted Rate of Return?

[woganmay]

Love this library! :)

Would it be possible to implement a Time-Weighted Rate of Return function? I'm working on a project that needs it. If I end up creating my own function, I'll just PR it here, but I'm sort of hoping that there's an existing function that can just be incorporated here.

[codeofsumit]

Looking for the same before building my own